Contriving a plausible motive for X to murder Y is much less difficult than convincing the reader or viewer that X might really be capable of doing it. Hence the enduring attraction of narratives powered by Eros rather than euros: money can't buy you unhappiness, but both men and women are only too well aware that once the former start thinking with the wrong head then all bets are off. One look at Fred MacMurray's face as he stands transfixed by the vision of Barbara Stanwyck's gold anklet descending the staircase near the beginning of Double Indemnity and you know the poor sap is doomed - as are the protagonists of these stylish, noirish thrillers from Finland and Spain.

In every other respect, they are as diverse as their cultures of origin. Lang is by far the more traditional: an intense psychological study of a successful novelist and TV celebrity in Helsinki who becomes involved with a single mother 20 years his junior, and by default with the violent, criminal ex-husband for whom she still has a soft (and heavily bruised) spot. When the book opens with Christian Lang phoning his best friend in the middle of the night with a desperate plea for the loan of a shovel, the astute reader already suspects that he probably isn't planning to thin out the begonias. So far, so formulaic. What lifts Kjell Westö's novel above that level is the way its climactic events are grounded in a detailed and utterly convincing depiction of the everyday.

David Lodge remarked that literature is mostly about having sex rather than having children, while life is the other way round. This is even more true of genre fiction, but Lang proves to be a worthy exception. There is plenty of very well-written sex, but everyone involved shows up burdened by the familiar messy heap of split and spilling baggage: kids, jobs, exes and family, plus the wan memory of better times past and the nagging dread of worse to come. Lang's career, both as writer and talk show host, is on the skids, but his malaise also has a wider dimension: he is both sickened and intimidated by the spectacle of "talented young people who do nothing but produce and consume useless goods and soulless entertainment" and haunted by the "fear of ageing and having his store of experiences declared worthless ... a fear that every adult westerner carries today".

In this context, his obsession with the equally tainted and problematic 25-year-old Sarita seems self-explanatory, and the eventual fatal encounter with her former husband, who is both jealous and envious of his successor, inevitable. Despite this, Westö's insights remain consistently fresh and convincing: "One sometimes finds like-minded souls, who have the identical answers and opinions as oneself, deadeningly boring, while one can find a paradoxical sense of connection with an opponent who has asked the same questions." Very occasionally a pallid gleam even breaks through the prevailing murk, as when Lang spends a few hours at the shops in downtown Helsinki buying food, light bulbs and "a novel by Siri Hustvedt - it was in a sale, he recalled". I have no idea what Paul Auster's wife has done to deserve being gratuitously remaindered by a fellow writer, but this may be a rare sighting of that elusive species, the Finnish joke.

Westö's dour narrator compares himself to Lang thus: "He was seen as the fast-moving, post-modern prize catch in the muddy sea of Nordic realism, where I made up a part of the nitrogen surplus."

How much of a prize catch Benjamin Prado represents is an open question, but the other two epithets certainly apply to him. Snow is Silent exemplifies the Eros-fuelled plot at its most structurally pure, stripped of all the extraneous cladding of social context and psychological credibility. Though less ambitious than Amis's London Fields and not nearly as wacky as Iain Banks' Walking on Glass, it shares with both the core conceit of an average bloke who is first set up and then coldcocked by a tantalising tease for reasons that he could not possibly hope to understand, thus adding intellectual insult to emotional injury. "I suppose most of you have been in love at some point and know in what that adversity consists. You think with your heart, you suffer with your brain. In other words, you become weak, but you also become dangerous."

But who becomes dangerous, and to whom? The ludic nature of Prado's project is blatantly signalled in the opening lines: "One of the three of us set off from his home last night, at about 11.30, to kill Laura Salinas. For the moment, I can't reveal his name or which of the three is me." The trio involved consists of a doctor, a wannabe novelist and a clerk in an insurance company who meet every evening at a bar, but the murder of Laura Salinas turns out to be a McGuffin and the apparent parallel with the plot of Lang - the abusive husband angle - in fact fulfils a quite different function in the story. The actual solution is likely to strike some readers as being as forced and improbable as those of Golden Age whodunits, but as with Christie & co, no clause ensuring verisimilitude appears anywhere in the implicit contract. In any case, it would be churlish to complain. Benjamin Prado offers a gripping, hip, undemanding read that touches lightly on the effects of our current cultural malaise in limpid prose that nevertheless seems to hint at, and perhaps even regret, all the things that are no longer sayable.